An evaluation was made of the feasibility of direct cell culture of human prostatic tissue as derived at autopsy. It is clear that such tissue, if obtained within 5 hours of death, while showing a somewhat higher bacterial content than surgical specimens, can be routinely cultured if a steady-state system is employed. It is proposed to continue these studies with attempts to investigate the histogenic types of cells as cultured from various sectors of the prostate - normal and malignant. Primary, human prostatic cells were successfully cultivated on collagen coated, sephadex "beads" in a 500 ml, controlled environment, suspension culture for 117 days. It is planned to expand this activity in accord with our stated objective. For this purpose, a new microcarrier has been developed. It is a "bead" made of pure, solubilized collagen. Critical evaluation is underway. Further efforts will be made to improve the culture environment. A unique and characteristic feature of human prostatic tissue is the copious secretion of citric acid. This peculiar capability, which appears androgen - dependent, provides both a qualitative marker for identification of prostate cells and a quantitative indicator of changing biological activity. In collaboration with Dr. R. Franklin, of Howard University, we have tested citricogenesis of cultured human prostatic epiehelial cells through assays of citrate levels in spent culture medium. We have found that, indeed, these cells, alone, develop such concentrations. Thus, assured that this marker is a dependable means for certification of viable histogenic types of prostate cells, we, in Buffalo, have undertaken an ongoing study of factors, especially hormones, which modulate the production and efflux of citrate from the cultured cells.